title: Functional properties of DOM in a stream draining blanket peat.
abstract: The functional properties of dissolved organic matter (DOM) from Rough Sike, a stream draining blanket peat in the northern Pennines, UK, were investigated using a series of 12 standardised assays. Nine stream samples were collected at different discharges during 2003--2006, and DOM concentrates obtained by low temperature rotary evaporation. Suwannee River Fulvic Acid was used as a quality control standard in the assays. Dissolved organic matter in high-discharge samples was more light-absorbing at 280 and 340 nm and adsorbed more strongly to alumina, than DOM characteristic of low streamflow, but was less fluorescent and hydrophilic, and poorer in proton-dissociating groups. No significant differences were found in light absorption at 254 nm, copper- or benzo(a)pyrene binding, or photochemical fading. Combination of the Rough Sike data with previously-published results for other streams and a lake yields totals of 20-23 values per assay, for a range of DOM types. For the combined data, variability in all the assays is significant (p < 0.001), as judged by comparison with variations in repeat measurements on the quality control standard. Analysis of the combined data shows that DOM hydrophilicity and adsorption are well-predicted by linear relationships with the extinction coefficient at 340 nm (E340), while good quadratic relationships exist between E340 and both buffering capacity and fluorescence.
authors.affiliation: Centre for Ecology and Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP, United Kingdom.
authors.forename: S A
authors.initials: SA
authors.lastname: Thacker
authors.forename: E
authors.initials: E
authors.lastname: Tipping
authors.forename: D
authors.initials: D
authors.lastname: Gondar
authors.forename: A
authors.initials: A
authors.lastname: Baker
mesh_terms: D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis*; D006812:Humic Substances / Q000032:analysis*; D012987:Soil / Q000032:analysis; D006113:United Kingdom; D014874:Water Pollutants, Chemical / Q000032:analysis; D053833:Wetlands
chemical_list: D006812:Humic Substances; D012987:Soil; D014874:Water Pollutants, Chemical